The disclosed embodiments relate to wireless systems and networks.
Cellular mobile telephony provides voice and data links between users of mobile devices and fixed devices on a network. It gives users mobility without regard to how they are actually connected to the network. This is done by providing access points or base station units (“BSU”) that can hand off the connections of mobile devices without interruption of the service. 2G (Second Generation) digital mobile phone service and AMPS (Analog Mobile Phone Service) are examples of such telephone networks.
Many limitations exist with such telephony networks. For example, while cellular mobile telephony networks generally provide service over large areas, such networks have limited capacity for the number of user devices that can be connected within the area covered by each BSU.
The bandwidth provided to users of this service is generally considered low bandwidth or “narrow-band access.” Thus, large data applications, such as transferring of large data files, cannot be effectively performed using such networks.
Providers of this service must acquire rights to use regulated radio spectra, often at high investment costs. Thus, employing such networks can be quite expensive for many applications or users.
This type of service is often unavailable or unreliable in certain areas, such as office buildings, convention centers and train stations, due to physical properties of these areas and/or due to the density of users seeking access to the service.
The Personal Communications Network (“PCN”) provides similar features to users of mobile devices, including voice and data links to a network, while providing mobility. PCN has a user model similar to that for cellular mobile telephony, so user behavior for one can be carried over to the other. PCN does not have the same limitations as cellular telephony. It offers wider bandwidth, or “broadband access,” and can provide greater availability with higher reliability in those particular areas where cellular telephony cannot. The RF spectra used by PCN is unlicensed, and no special access rights are required.
PCN uses wireless networking technology, including IEEE 802.11, which uses direct-sequence spread spectrum, and Bluetooth, which uses frequency-hopping spread spectrum. Importantly, however, the Bluetooth wireless standard does not support movement from one area of coverage or “cell” to another.
Currently, the most well-known attempt to provide features that PCN offers in a mobile environment is referred to as 3G-(third-generation) wireless. 3G-wireless, however, is constrained by factors that do not constrain PCN implementations. These include heavy investment for the acquisition of spectrum usage rights.
PCN poses its own problems, including the mobility problem and handoff.
A link established between a mobile unit and a base station unit of a PCN is based on a complex set of properties shared between the mobile unit and the base station unit. Relatively simple AMPS cellular telephone service supports mobility without the active support of the mobile units, but the properties of the links are very simple. 3G-wireless service employs the active participation of the mobile unit to provide mobility, while the properties of the links for this type of service more closely resembles the properties of the links in PCN.
Thus, there is a need for a wireless networking system that solves the above problems, while providing the above benefits, as well as providing other advantages.
In the drawings, the same reference numbers identify identical or substantially similar elements or acts. To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the Figure number in which that element is first introduced (e.g., element 204 is first introduced and discussed with respect to FIG. 2).
Note: the headings provided herein are for convenience and do not necessarily affect the scope or interpretation of the invention.